It is well known that infectious agents such as viruses and bacteria can be transmitted from one person to another through re-use of incompletely sterilized medical instruments, such as dental hand tools, syringes, and the like. As it is difficult to completely sterilize complex tools, such as air-driven dental hand tools, an effort has been made to make available disposable dental hand tools that are to be used with only one patient and then discarded. It is argued that such hand tools, if made of inexpensive plastic and not designed for an extended life, would become practical and inexpensive enough for use in many common dental procedures.
For example, U.S. Pat. No. 3,955,284 to Balson on May 11, 1976, discloses a disposable dental drill assembly. The advantages of such a disposable drill assembly, as disclosed, are based on economics, as opposed to patient and practitioner safety, and are motivated by the relatively high cost of purchasing a plurality of expensive, machined, extended-life hand tools. It is argued that such a disposable dental assembly, while not as durable as an expensive machined dental drill assembly, is more economical due to its inexpensive manufacturing cost. No mention is made, however, of using one such disposable drill assembly per patient to avoid infection.
As the concern over infectious disease has become more prominent, and injection molding techniques have become more refined and less expensive, other disposable dental hand tools have become available. U.S. Pat. Nos. 4,795,343 and 4,842,516, both to Choisser on Jan. 3, 1989 and Jun. 27, 1989, respectively, are examples of such disposable hand tools meant for use on a single patient specifically to reduce the risk of spreading disease. While such devices can be manufactured relatively inexpensively, such devices are also quite limited in their functionality.
For example, dental burs or diamond cutting tools of such devices are permanently mounted to a drive turbine, necessitating the use of as many such devices as dental burs are required for a particular patient. As single dental procedure may easily require five or more different types of dental burs, such as drill bits of varying sizes and shapes, polishers, prophylactic angles, and the like, a practitioner may have to use five or more such disposable hand tools for a single patient, subsequently discarding all of them.
Moreover, such devices are limited to supplying an air stream for driving a turbine attached to the bur. Frequently, however, it is necessary to flush the work site with air and water. Consequently, using such devices requires additional water and air supplying implements, and causes further congestion in the already crowded working environment of a person's mouth. Further, the means by which rotation is imparted to the turbines of such devices provides less torque than many conventional hand tools.
A further drawback of such disposable devices is evident in that it is often difficult to properly illuminate a person's mouth when a number of implements are inserted in the mouth. Yet such disposable dental hand tools provide no means of illuminating the work site. Consequently, while devices of this type do help reduce the risk of spreading diseases between patients, the lack of functionality inherent in such devices requires additional expense, equipment, and time on the part of the dental practitioner and, therefore, the patient.
Clearly, a disposable dental hand tool is needed that overcomes the drawbacks of those devices found in the prior art. Such a needed device would be inexpensive to manufacture, thereby making it practical to dispose of after use with one patient. Moreover, such a needed device would allow the replacement of different dental burs, making it unnecessary to use more than one such device for each patient. Further, such a needed device would allow the insertion of burs of various sizes and shapes, and would make removal and insertion of such burs easy to accomplish without significantly increasing the size of the device. Still further, such a needed device would provide means of delivering water, air, and light to the work site. Such a needed device would additionally provide a high degree of torque and control to the dental bur, making it easy for the dental practitioner to use. Still further, such a needed device would be light weight, easy to grasp and manipulate, and easy to connect to a standard source of air, water, and light. The present invention fulfills these needs and provides further related advantages.